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Newsletter

DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN

No. 1/2009 (Jan. 5, 2009)

MHP - a difficult road to interactive TV. A few years ago many predictions showed a rapid development of interactive television. Unfortunately, the plans have proved to be greatly exaggerated and the demand for these services is still small. But in recent months, experts predict a faster development of this technology and services based on it. Interactive TV provides, together with the stream of audio and video, special applications allowing for additional services. The most common are: paid video (VoD, PPV), information services, games, voting systems, e-mail, remote shopping. By their nature, these additional services require a return channel. Interactive set-top-boxes may use for this purpose the traditional technologies to access the Internet, or - as in the case of DVB-RCT (Return Channel Terrestrial) terminals - can send the data wirelessly back to the DVB-T infrastructure supporting such an option.

Interactive television - the subscribers will be able to arrange their programs, including TV schedules: "My television, my programs, my schedule" - says the woman from the Alcatel's poster.

A promising technology in the field of interactive television is MHP - an open Multimedia Home Platform - which is a part of the DVB project. MHP is the middleware software enabling communication of interactive applications with the operating system of the set-top-box. The signal reaching the receiver is processed by the utility called Application Programming Interface (API). The concept of open system provides a lot of flexibility for equipment manufacturers and TV operators, both in the choice of applications and in the details of their implementation. Despite the consensus on the importance of an open technology, there is more popular commercial solution - OpenTV - implemented in about 100 million set-top-boxes. Lack of MHP equipment on the market hampered the launch of services. Interactive digital DVB-T receivers based on MHP standard are most popular in Italy, reaching 2 million. The popularity of these devices is the result of a controversial subsidy scheme. The purchase of a DVB-T receiver with interactive capabilities and access to the return channel has been subsidized by the state. The price reduction diminishes the difference between the MHP equipment and other, non-MHP receivers. The equipment based on MHP is provided by a number of manufacturers including ADB, Philips, Strong, Humax. In Poland, MHP solutions have been implemented by the satellite "n" platform and some cable networks - Multimedia, INEA and Vectra. The development of MHP promises a significant change of the trend in the near future. There are two directions - the first one is to simplify application development - in this field the main player is Sun Microsystems. The company has developed a new platform called JavaFX that facilitates application design. The second direction includes further universalization of the MHP, which results in rules of Globally Executable MHP (GEM). They will allow to use this platform in many promising areas, from Blu-ray technology to MHP-related OpenCable Application Platform (OCAP), being the basis for "tru2way" services available now in the US cable TV networks. It may significantly boost market expansion of this technology.

Interactive applications are the core of IPTV

Wooden Eiffel tower. The tower is a unique engineering solution on a global scale. Built in 1935 with larch wood, it is probably the largest wooden structure in the telecommunications world. It is 111 meters high, at the base of 20 x 20 meters. Other similar objects were either destroyed during the war, or were demolished and replaced by newer steel structures. The beams have been joined with brass screws (without a single iron nail!). Due to the impact of antenna inductance, no ferromagnetic materials were used - the tower was originally built for medium-wave broadcast antenna. For over ten years now the tower is used for modern radio communications (mobile phones, radio taxi services etc). Where is this tower? - The answer at the end of this issue.

Night view of the largest wooden tower in the world. Illuminated by eight spotlights, it fascinates everyone with its beauty. (source: www.inzynierbudownictwa.pl)

Multiswitch installations in multi-family houses. The most flexible multiswitch installations in multi-story buildings are based on 9-cable system. But similar properties are also available in the case of cascadable multiswitches, first of all scalability and possibility of easy expansion of the system. The installation seen in the diagram below allows reception of any available terrestrial or satellite program in every outlet. The MS-952/951 multiswitches (for two satellites) enable the designer/installer to build extensive SMATV systems with a hundred or so outlets. So large installations require to use additional amplifiers.There are available TERRA or Signal amplifiers (for two satellites - R694491). The amplifiers allow to adjust signals in terrestrial and satellite bands. The channel amplifiers of ZG series allow to obtain the best possible parameters of terrestrial broadcasts.

Multiswitch installation in a multi-family house

IP CCTV - a 21-camera system in household goods factory. The manufacturer and distributor of plastic and wooden household articles - KONEX company, asked the DIPOL branch in Sandomierz to design and run a video surveillance system. The conditions that the system had to comply with included capability of precise monitoring of large areas and possibility of easy expansion in the future. It has been decided to use IP ACTI cameras ACM-1311 K1117 equipped with IR illuminators. Their 1/3" SuperHAD CCD sensors ensure horizontal resolution of 420 TVL, enabling precise observation even at low light conditions. MPEG-4 SP compression allows economic transmission and recording of high-quality video data. The system is managed by free ACTI NVR software (up to 64 channels). The 21 identical cameras are connected in a fixed wired network. The designed and implemented system has satisfied all the requirements of the investor.

IP CCTV in VLANs. Security of IP CCTV system and high network efficiency are easier to maintain in VLAN (Virtual Local Area Network). VLAN is logically separated network (Layer 2) from a larger physical structure. To create such networks one uses manageable/configurable switches allowing to group the ports that can communicate. The networks can be based on several such switches. For example, IP cameras, the recording server and managing computer (of the operator) are grouped into one VLAN, and the rest of the network devices - into a second VLAN. The users of the second network will not be able to get access to the IP CCTV data.

IP CCTV uses dedicated VLAN1

ULTISYSTEM - a unique and honored surveillance software - support for E-maps.ULTISYSTEM provides built-in E-map function. This kind of "synoptic chart" is a tool that allows to design a graphical map showing the deployment of cameras, the states of alarm inputs/outputs and audio channels. From the level of the map it is possible to control the relays. The background of the E-map can be obtained from jpg, gif or png files, such as satellite pictures, various kinds of maps, site plans etc.

E-map

Conversion/expansion of analog CCTV into IP system. Extension of an existing analog CCTV installation is often a troublesome task. The reasons include low video quality and lack of free channels in the DVR. The simplest solution is to "replace" the DVR with an NVR (Network Video Recorder). It requires to employ video servers between the cameras and the NVR. Depending on the needs, one can use 1-channel (K2113), 4-channel (K2118), or 8-channel (K2119) video servers. All these devices allow to convert the video into IP streams (MPEG-4) at 25/30 fps, with D1 resolution.

ULTIAIR - WISP mode. If the Internet is going to be distributed wirelessly, we will need an AP with WISP (Wireless Internet Service Providers) mode enabling routing and development of the internal network. The professional devices of ULTIAIR series are suitable not only for large service providers, but may also be used in small networks, with isolated client stations. Thanks to integration of the electronics and the antenna, the devices are highly efficient. These compact APs are easy to mount (PoE solution) and weather-resistant, ensuring long-term, maintenance-free operation.

WISP mode in ULTIAIR device. The user (1) connects with AP (2) which enables Internet access. The switch allows to connect next computers to the network based on ULTIAIR.

TP-LINK - change the default name and password. To avoid unauthorized access to a TP-LINK device the user has to change the default User Name and Password (default strings: admin/admin). Go to System Tools/Password window, and one by one enter the old (default) strings and then the New User Name, New Password and its confirmation. Save changes by clicking Save.

Gliwice, Upper Silesia, Poland - the Gliwice Radio Tower. The tower went down in history in 1939, because of the events that took place in the nearby radio station building. On August 31, 1939, at 20:00 local time, the German radio station in Gleiwitz (since 1945: Gliwice, Poland) was attacked by seven SS troops in civilian clothes, who pretended to be Polish rebels. Their goal was to announce that Poland started the war with Germany, which would have exempted France and Britain from the obligation to provide military aid to Poland. The event is known as the Gleiwitz incident.

Gas/petrol stations - why they cannot be run without IP CCTV. Nowadays they are practically 100% self-service stations. That's why video surveillance system is indispensable - covering the gas/petrol pumps, cash desks, shopping area, car wash, compressor etc. The video has to be recorded and stored for some time... - archive DWR of Feb. 18, 2008